Vortex control



0a .23, 1934.- s. H. DOWNS VORTEX CONTROL Filed March 14, 1932 2 Sheets-Sheet 1 s. H. DOWNS VORTEX CONTROL Filed March 14. 1932 Oct. 23, 1934.

2 Sheets-Sheet 2 INVENTOR Jawd/ /1 Downs BY ATTORNEYS Patented o... 23, 1934 UNITED STATES von'rEx contract.

Seweil H. Downs, Kalamazoo, Mich, assignor to Clarage Fan Company, Kalamazoo, Mich.

Application Mai ch 14, 1932, Serial No. 598,784

rile mainbbjects of this invention are:

First, to provide adjustable means for controlling the volume of air admitted to a centrifugal fan.

Second, to provide such means of a nature that will increase the efliciency of, the fan when it is used at a capacity below maximum to eflect a power saving.

Third, to provide, such means adapted to be placed in the inlet of the fan to cause a swirl of the admitted air in the direction of rotation of the blades of the fan. v

Fourth, to provide such means integral with the vortex inlet cone of a fan.

Fifth, to provide simple controlling and opcrating means therefor.

\ tion will appear from a consideration of the de- Further objects and advantages of the invenscription to follow and the drawings, in which:

Fig. 1 is an elevation of a centrifugal induction fan incorporating the invention.

Fig. 2 is a view in section of the invention with the controlling blades in open position.

Fig. 3 isan elevation from the left side of Fig.

2 of the volume controlling and closure means.

, Fig. 4 is a detail sectional view ofa portion of the means for operating and controlling the blades taken on line 4-4 of Fig. 5.

Fig. 5 is an elevation from the right side of Fig. 4 partly in section.

Fig. 6 is a detail view of a portion of the operating and controlling means.

Fig. 7 is a detail sectional view of a modifled form of the invention showing a diflerent arrangement for operating and controlling the blades.

The parts will be identified by their numerals of reference, which are the same iii all the views. 7

1 represents a centrifugal induction fan of conventional design having-a casing 2 and a fan wheel 3 designed for rotation in a clockwise direction when viewed from the inlet of the fan or the left side of Fig. 1. The fan wheel is supported by a bearing and support 4 andthe inlet opening for the fan is represented at 5.

Disposed in the inlet opening is a vortex inlet cone 6 of special construction having a conventional flange '7 for directing the flow oi incoming air to the fan wheel and to prevent leakage from the fan back through the inlet. 8 is an extended external flange adapted to support the closure means and the actuating mechanism and to direct the flow oi air to the blades of the device. It is desirable to support the closure means and actuating mechanism therefor on a single vortex inlet cone but, without departing from the spirit of this invention, the

usual inlet cone could be used with a separate and distinct supporting means for the clo- 3 Claims. (cl. 230-114) sure device adapted to be joined to said inlet cone.

The closure means is supported by means of a spider hub 9 supported centrally of the inlet cone 8 by means of spider rods 10. In the drawings these rods are illustrated as being threaded into a tapped hole in the spider hub, but any suitable fastening device could be used. The spider rods at their outer endsv pass through holes 11 in the inlet cone 6 and are provided with adjusting nuts 12 adapted to properly center and adjust the position of the closure means.

In the device shown in Figs. 1-5, the spider hub 9 and the rods 10 are so arranged as to form a framework for a conical closure with the spider hub 9 as the vertex of the cone and the rods 10 as elements of the conical surface.

In the modification shown in Fig 7 the rods 10 and the hub 9 are so arranged that they fall substantially in a single plane.

Blades or vanes 13 are provided to act as closure means or directional vanes. These blades are provided with bearings 14 and 15 and are trunnioned on the spider rods 11 for rotation about the rods.

In the construction illustrated there is a plurality g5 of spider rods to support the hub 9 and for convenience in manufacture a rod is provided for each blade 13 of the closure means, because there need be but one type of blade manufactured; It is obvious that fewer rods than blades could be provided and the blades might be joumaled in the vortex inletr cone 6 and the spider hub 9 in any suitable manner which will be apparent to anyone skilled in the art, or that the spider hub 9 could be supported in position in a variety of ways.

The blades 13 here illustrated are substantially in the form of a sector of a circle, although any desired shape that will close'the openings and cause a swirl of the incoming air inthe direction of rotation of the fan wheel can be used, depending upon' the shape of the inlet orifice that it is desired to control or close. For a circular opening these sectoral shaped blades have proven very satisfactory, and since this is the usual to swirl the air in the proper direction and the.

overlap tends to close the inlet of the fan, when the closure is partly opened, to air that is not swirling. A

There is provided a simple means for rotating the blades in unison. In the form of the invention shown in Figs. 2-5 a bevel gear 16 is mounted for rotation on the spider hub 9 and each blade is provided with a pinion 17 adapted to engage the gear 16, whereby a rotation of one blade will ef-- drawings is shown as a bevel gear to mesh with the gear 116. The spider hub ,9 and the gear 16 and the pinions 17 are encased in a housing com.- posed of the halves 25 and 26 held together by a bolt 27 and nut 28 which are used for mounting the gear 16 on said hub.

For manual operation of the blades there is provided an operating bracket 18 fastened to one of the blades. In the drawings this bracket is shown bolted or screwed to its blade by means of bolts or screws 19, although rivets or any suitable means of attachment can be utilized. An operating rod 20 extends from this bracket and through a slotted guiding quadrant 21. An operating handle 22 is provided which in the drawings is shown as a lever pivoted on the end of one of the rods 10 and engaging the operating rod 20. The operating rod 20 is provided with a nut 23 and a thumb nut 24 between which the handle and the guiding quadrant may be clamped by tightening the nut 24 to hold the blade in the desired position. It is clear to one skilled in the art that any type of operating and holding means maybe used without departing from the spirit of the invention,

and it is not essential that the blades be moved manually, but any controlling means could be utilized.

Theinvention herein described has proven especially useful in increasing the eiilciency of induction fans used for' moving quantities of air. In the usual type of fan, the air enters the inlet and has to change direction degrees or more. and is then caught by the blades of the fan wheel and urged around the volute and through the outlet. The amount of energy required to change the direction of flow is considerable.

It has been found that in using a centrifugal fan to handle less than its capacity the use of the present invention to cut down the supply also tends to swirl the air as it enters the fan, eliminating the power loss attendant upon the use of the regular damper. At about one-half capacity the power required is reduced by very nearly 50 percent over that required with a simple damper control of the flow.

In using the present invention it is essential that the vanes be so arranged that any swirling of the air is in the direction of rotation of the fan wheel, and it is to insure this that the overlapping of the blades is arranged as described. It is impossible with the overlap as it -is to obtain a swirl counter to the rotation of the fan wheel.

The invention also makes it possible to swirl all air without eddy currents at any desired rate of flow of incoming air by adjustment to allo passage to the fan of only suflicient air.

It has also been demonstrated-that the use of the overlap prevents any air from entering the fan in a direction perpendicular to the wheel as there is no appreciable leakage past the ends of the overlapping blades. The specific form of control has been demonstrated to be of great utility because of its simplicity of operation, and the use of the quadrant makes it possible to limit the movement of the vanes to such an extent that at no time does the air receive from the blades themselves a swirl in a direction opposed to the rotation of the fan.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a vortex control means located in the inlet of a centrifugal fan and adjacent the 'fan wheel to impart to the entering air a swirl in the direction of rotation of said fan wheel and to con trol the volume of air handled by the fan, the combination of a skeleton spider comprising a plurality of spider rods and a central bearing hub, said rods extending from the periphery of the inlet of the fan to said bearing hub centrally of said inlet and constituting the sole support for the bearing hub and control means, a plurality of substantially sector-shaped sheet metal blades each having bearings thereon, whereby each blade is journaled on a spider rod, each blade carrying a pinion adjacent said bearing hub, a bevel gear journaled on said bearing hub and engaging all of said pinions, and means for rotating said bevel gear whereby all of said blades are rotated simultaneously.

2. In a vortex control means located in the inlet of a centrifugal fan and adjacent the fan wheel to impart to the entering air a swirl in the direction of rotation of said fan wheel and to control the volume of air handled by the fan, the combination of a skeleton spider comprising a plurality of spider rods and central bearing hub, said rods extending from the periphery of the inlet of the fan to said bearing hub centrally of said inlet and constituting the sole support for the bearing hub and control means, a plurality of substantially sector-shaped blades each journaled on one of said spider rods and carrying a pinion adjacent said bearing hub, a bevel gear journaled on said bearing hub and engaging all of said pinions, and means for rotating one of said blades whereby said pinion is rotated to rotate all of said blades simultaneously.

3. In a vortex control means located in the inlet of a centrifugal fan and adjacent the fan wheel to impart to the entering air a swirl in the direction of rotation of said fan wheel and to control the volume of air handled by the fan, the combination of a skeleton spider comprising a plurality of spider rods and a central bearing hub, said rods extending from the periphery of the inlet of the fan to and supporting a bearing hub centrally of said inlet and forming a substantially conical framework with its apex pointed in a direction counter to the direction of flow of air to said inlet and constituting the sole support for the bearing hub and control means, a plurality of substantially sector shaped blades each journaled on one of said spider rods and carrying a pinion adjacent said bearing hub, a bevel gear journaled 'on said bearing hub and engaging all of said pinions, and means for rotating said gear whereby all of said blades are simultaneously 

